Jet propulsion engine with variable baffles and fuel supply



April 12, 1966 F. c. 1. MARCHANT 3,245,218

JET PROPULSION ENGINE WITH VARIABLE BAFFLES AND FUEL SUPPLY Filed May20, 1963 s Sheets-Sheet 1 A ril 12, 1966 F. c. 1. MARCHANT 3,245,213

JET PROPULSION ENGINE WITH VARIABLE BAFFLES AND FUEL SUPPLY 8Sheets-Sheet 2 Filed May 20, 1963 April 12, 1966 F. c. MARCHANT 3,

JET PROPULSION ENGINE WITH VARIABLE BAFFLES AND FUEL SUPPLY Filed May20, 1963 8 Sheets-Sheet 3 F/GJ 46 65 D 32 47 DEIUUSZ 49 117 50 [lUU[7- 70 2 /6 April 1966 F. c. I. MARCHANT 3,245,218

JET PROPULSION ENGINE WITH VARIABLE BAFFLES AND FUEL SUPPLY Filed May20, 1963 8 Sheets-Sheet 4.

April 12, 1966 F. c. 1. MARCHANT 3,245,213

JET PROPULSION ENGINE WITH VARIABLE BAFFLES AND FUEL SUPPLY Filed May20. 1963 8 Sheets-Sheet 5 April 12, 1966 F. c. I. MARCHANT 3,245,218

JET PROPULSION ENGINE WITH VARIABLE BAFFLES AND FUEL SUPPLY Filed May20, 1963 8 Sheets-Sheet 6 April 1966 F. c. l. MARCHANT I 3 ,245,2l8

JET PROPULSION ENGINE WITH VARIABLE BAFFLES AND FUEL SUPPLY Filed May20, 1963 8 Sheets-Sheet 7' F/G/O E [m U K DUI] F/G/J I lo 44-\ Q45 70 32Li April 12, 1966 F. c. 1. MARCHANT 3,245,218

JET PROPULSION ENGINE WITH VARIABLE BAFFLES AND FUEL SUPPLY Filed May20, 1963 8 Sheets-Sheet 8 United States Patent JET PROPULSION ENGINEWIIH VARIABLE BAFFLES AND FUEL SUPPLY Francis Charles Ivor Marchant,Bristol, England, assignor to Bristol Siddeley Engines Limited, Bristol,England, a British company Filed May 20, 1963, Ser. No. 281,732 Claimspriority, application Great Britain, June 5, 1962, 21,687 62 8 Claims.(Cl. 60-3555) The invention relates to the provision, in an aircraft jetpropulsion power plant including an axial flow air compressor arrangedto deliver air to an annular section passage, of means for burningliquid fuel in the passage when desired in order to increase the jetthrust.

According to the invention a plurality of struts or pillars are providedspaced around the passage and projecting into it transversely .to thedirection of airflow therethrough, eachstrut or pillar carrying a pairof perforated bafifles extending downstream of the strut or pillar andarranged .forrelative swinging movement from an open Vj position, withthe strut or pillar constituting the apex of the V, to a closed togetherposition, and means for dispersing fuel -either..into the V-shaped spacebetween each pair of :bafiles when open, or into the air flowing throughthe perforations of the baffles into that space, for combustion therein.

When fuel is not being burnt in the passage, the perforated baffles areclosed together to reduce obstruction to the airflow.

. The pairs of baflles may be moved into or out of their operativepositions simultaneously or in groups according to the amount of heatingrequired.

The invention is particularly applicable to power plants in which theaxial flow compressor is arranged to deliver air to an annular sectionpassage divided into inner and outer annular parts by a partition wallextending downstream from a leading edge spaced from the compressor, theouter part of the passage being connected to at least one stub ductextending outwards from the axis of the compressor to an outlet carryinga swivelling nozzle. In this case the struts or pillars carrying thebaflles project into the outer part of the passage adjacent to theleading edge of the partition Wall. The combustion thus takes place asfar upstream of the swivelling nozzle or nozzles as possible, anddifficulties due to local overheating of the nozzles are minimised.

Another example of a situation to which the invention is applicable is apower plant of bypass type, having an annular air discharge nozzlearound the jet nozzle, and having means for burning fuel in a part ofthe bypass passage a little upstream of the nozzle, so as to augmentthrust when required.

The accompanying drawings show examples of equipment according to thepresent invention. In these drawmgs:

'FIGURE1 is a diagrammatic underneath plan of a power plant in place inan aircraft;

FIGURE 2 is a half section of part of the power plant on the line *]1IIin FIGURES 1 and 3, omitting the swivelling part of the nozzle;

FIGURE 3 is a longitudinal section of part of the power plant on theline III---I-II in FIGURE 2;

FIGURE 4 is a developed sectional view, corresponding to the lines IVIVin FIGURES 2 and 3, through the fuel burning equipment, with the bafflesin the open position;

FIGURE '5 a corresponding view with the baflles in the closed togetherposition;

FIGURE 6 is a fragmentary diagrammatic view of operating mechanism, seenfrom the line VI-VI in FIG- URE 2;

ice

FIGURE 7 is a fragmentary section on the line VII VII in FIGURE 6;

FIGURE 8 is a view, similar in nature to FIGURE 6, showing analternative arrangement;

FIGURE 9 illustrates an alternative fuel dispersing arrangement;

FIGURE 10 and FIGURE 11 illustrate another alternative, FIGURE 11 beinga section on the line XIXI in FIGURE 10;

FIGURE 12 is a developed sectional view, similar in nature to FIGURES 4and 5, showing a modified arrangement of the baflles; and

FIGURE 13 shows another modification.

The power plant shown in FIGURES 1 to 3 includes a low pressure axialflow compressor or ducted fan having a final row of moving blades 10followed by a row of stator blades 11. Air leaving the stator bladesflows through an annular-section passage 12 divided into inner and outerannular parts -13 and 14 respectively (FIGURE 3) by a partition wall 15extending downstream from a leading edge 16 spaced from the blades '11.The air flowing through the inner passage :13 passes through a highpressure compressor comprising a row of inlet guide vanes 17, andseveral rows of rotor blades 18 (only the first and last of which areshown in FIGURE 3) with intermediate stator blades 19. After dischargefrom the high pressure compressor the air passes through a combustionsystem 60 and high and low pressure turbines 61, 62. The high pressureturbine drives the rotor 20 of the high pressure compressor which isjournalled at its forward end in a bearing 21 carried by a diaphragm -22projecting inwards from the inner wall 23 of the duct 13, while the lowpressure turbine drives a shaft 24 journalled in a bearing 25 and towhich the low pressure compressor rotor 26 is attached.

The outer passage 14 is closed at its rear end 27 but has two stub ducts28 (one of which appears in FIG- URES 2 and 3), each extending obliquelyoutwards from the axis 29 of the engine to an outlet 30 to which aswivelling nozzle may be attached (as shown at 63 in FIGURE 1), thearrangement being preferably as described in the complete specificationaccompanying our co-pending patent application No. 159,106, now PatentNo. 3,153,906, that is to say with the swivel axes 31 of the nozzlessymmetrically arranged on opposite sides of the engine, dropped somewhatbelow a horizontal plane through the engine axis 29 and divergingrearwards.

The passages 12, 13 and 14 are partly formed in a casing sectioncomprising the inner wall 23, a leading edge part of the partition wall15 and an outer wall 32, these walls being interconnected by six hollowradial struts 33 of generally streamlined cross section. Two of thesestruts are shown in the developed section of FIGURES 4 and 5.

For the purpose of permitting fuel to be burnt in the outer passage 14as far upstream from the swivelling nozzles as possible, there ismounted at the trailing edge of each strut 33 a pair of baffles 34 and35 (see the lower part of FIGURE 3 and FIGURE 4) provided withperforations 36 and internal deflectors 37. The baflles are attached toco-axial tubes 38 and 39 supported at their inner ends in bearingsockets in the partition wall 15 and projecting through the outer wall32 to receive operating levers 40 and 41 whereby they may be movedindividually from an open V position as illustrated in FIGURE 4, for usewhen fuel is being burnt, to a closed together position as illustratedin FIGURE 5, in which obstruction to the airflow is reduced when fuel isnot being burnt.

To supplement these baflles there are provided, in the space betweenadjacent struts 33, two further pairs of baflies 42 and 43 (see theupper part of FIGURE 3),

similarly mounted on co-axial tubes 44 and 45, constituting pillars,provided with operating levers 46 and 47.

In the region of the bafiles and for about an equal distance downstreamof them, inner and outer liners =3 and 49 are provided, spaced atsuitable distance from the walls 15 and 32 so as to convey secondaryand/or dilution air to a region downstream of the primary combustionzone in the Wake of the baflles, and also to protect the passage wallsfrom overheating. In the regions of the stub outlet ducts 28, the outerliner 49 is lipped outwards as illustrated at 59 in FIGURES 2 and 3 tocontrol the direction of discharge of the hot gases into the stub ducts.The liners can be perforated if desired.

The co-axial tube assembles 38, 39 and 44, 45 may also constitute fuelsupply ducts, receiving liquid or gaseous (eg. vaporised) fuel throughpipe connections 50 (FIGURE 3) on the outside of the casing 32 and beingprovided with one or more orifices 51 to disperse a spray of fuel intothe V-shaped space between the bafiles. Alternatively, as shown inFIGURES 9 and 13, the orifices may be arranged at 51a to disperse fuelin the upstream direction so that it is carried into the V-shaped spacesby the air flowing through the perforations 36. Separately mounted fueldispersing devices mounted upstream or downstream of the pillars mayhowever be used if desired, for example as shown at 64 in FIGURES l0 and11.

The operating levers 40, 41, 46 and 47 may each carry a cam-followerroller engaging in a cam track 67, 68 in a ring 65 (FIGURES 2, 6 and 7)surrounding the casing 32 and rotated about the axis 29 of the engine bysuitable means, such as a pinion 66, while supported by rollers 70. Thecam tracks may be arranged either, as in FIG- URE 6, to move all thebaffies simultaneously into or out of their operative positions, or, asin FIGURE 8, to bring successive pairs or groups of baffles intooperation in dependence upon the setting of a power control member, fuelsupply selector valves (not shown) being operated simultaneously tosupply fuel to the dispersion means pertaining to each pair of bafflesas it reaches its operative position. In FIGURE 8, the first half of thedownward movement of the portion of the ring 65 shown causes opening ofthe baffles associated with the vanes 33 by means of cam tracks 67a,6811, while the second half of the downward movement causes opening ofthe remaining bafiies by means of cam tracks 67b, 68b.

Each pair of baifies or group of pairs of baffles to be brought intooperation initially is provided with a separate ignition means, whichmay be a torch igniter projecting into the V-shaped space between a pairof baffles, as shown at 69 in FIGURES 8, 10, 11 and 13. The bafiles arepreferably shaped, as shown, so that in their operative positions theirtrailing edges 52 engage the trailing edges of adjacent baflles to forma continuous wake zone around the annular passage 14, thus promoting thespread of flame from one V-shaped space to the next. This means that theedges 52 are inclined outwards and rearwards. Those bafiies in theregion of the stub outlet ducts may have a trailing edge part cut awayas shown at 52a to avoid an undesirably great projection into the stubducts, and to direct dilution air into the central part of the stubducts.

FIGURE 12 illustrates an improved arrangement of the struts and bafllesand is a diagrammatic development of half of the cylindrical surfaceindicated by the section lines XII-XII in FIGURE 2, except that in thisembodiment, as described below, the six vanes 33 are replaced by eightstruts. The chain-dotted line 53 represents the upper intersection ofthe cylindrical surface with a vertical plane through the axis 29 of theengine, and the line 54 the lower intersection. The stub outlet ductopening is seen at 55, and it will be understood that the other half ofthe development is a mirror image of FIGURE 12 about either of the lines53 or 54.

In this arrangement there are four equally spaced principal strutsextending across the passages 12, 13 and 14,

the top and bottom struts being fiat and lying in radial planes, and theside struts 33a being curved to offset unequal flow distribution betweenthe upper and lower halves of the passages 12 and 14 due to the stubduct outlets 55 being displaced below the horizontal plane through theaxis 29 of the engine. Between the principal struts there is a smallerlower-quarter strut 56 on each side which is also flat, and anupper-quarter strut 56a on each side which is curved to improve the flowdistribution. Each of these struts 33, 33a, 56 and 56a carries a pair ofperforated trailing edge baffles 34 and 35 which in their closedtogether positions form a continuation of the profile shape of thestruts. Between each of these pairs of bafiles a further twosupplementary pairs of baifies 42 and 43 are provided, the arrangementbeing generally similar to that illustrated in FIGURES 4 and 5 exceptthat, in the closed together positions, the pairs of bafiies are alignedwith the general fiow directions determined by the struts 33, 33a, 56and 56a and their associated baffles. Where the closed togetherpositions are displaced from radial planes, the bafiles of each pair aremade unequal in length so that in the opened positions, indicated bydotted lines, the trailing edges of adjacent battles can engage oneanother as described in connection with the first arrangement. Thisfeature can be omitted in the upper quarter of the passage 14 where theflow velocities downstream of the baffies are some? what lower thanthose nearer the outlet ducts.

There may be struts or pillars additional to those which carry baflles.In particular, as shown in FIGURE 13, the tube assemblies 44, 45carrying the bafiles may all be separate from the struts 3312, thestruts 33b being located between two pillars. This allows a degree ofindependence of choice of the location of the baflies and of the strutsin the up-and-downstream direction. In particular the V-shapedcombustion zones may be arranged further upstream without subjecting thevanes 33, which are stress carrying members, to additional heating.

I claim:

1. An aircraft jet propulsion power plant including means defining anannular section passage, an axial flow air compressor arranged todeliver air to the passage, a plurality of elongated members spacedaround the passage and projecting into it transversely to the directionof airflow therethrough, pairs of perforated baffles extendingdownstream of each member, means mounting each pair of baffles on thecorresponding member for relative swinging movement from an open Vposition, with the member constituting the apex of the V, to a closedtogether position, means for dispersing fuel to reach the V-shaped spacebetween each pair of baffles when open for combustion in that space, atleast one stub duct extending outwards from the axis of the compressorto an outlet carrying a swivelling nozzle, and means connecting saidpassage, downstream of said pairs of baffles, to said stub duct.

2. A plant according to claim 1 including means for bringing successivepairs of baffles into operation in dependence upon the setting of apower control member.

3. A plant according to claim 1 in which at least most of the bafilesare shaped so that in their operative positions their trailing edgesengage the trailing edges of adjacent baffles.

4. A plant according to claim 1 in which the means for dispersing fuelincludes orifices in the mounting means of each pair of baffles.

5. A plant according to claim 1 in which, in the region of the battlesand for a distance downstream of them, there are inner and outer linersspaced from walls of the passage.

6. A plant according to claim 1 in which the annular section passage isdivided into inner and outer annular"; parts by a partition wallextending downstream from a leading edge spaced from the compressor, theouter part of the passagebeing connected to said one stub duct, aresubstantially aligned with the local air flow as inand the memberscarrying the baffles project into the outer fluenced by the presence ofthe stub ducts. part of the passage adjacent to the leading edge of thepartition 11 References Cited by the Examiner 7. A plant according toclaim 5 in which the passage 5 UNITED STATES PATENTS is connected to atleast one stub duct extending outwards 2 835 108 5/1958 Karen 6039 72from the axis of the compressor to an outlet carrying a 2866313 12/1958H011 6 swivelling nozzle, and, in the region of each stub duct,2:875:580 3/1959 Moy the 1511PPed outwards- 2,899,799 8/1959 Setterblade6039.72

8. A plant according to claim 6 including means for 10 actuating thebafiies so that in their closed positions they DONL'EY J. O I G primaryExaminer

1. AN AIRCRAFT JET PROPULSION POWER PLANT INCLUDING MEANS DEFINING ANANNULAR PASSAGE, AN AXIAL FLOW AIR COMPRESSOR ARRANGED TO DELIVER AIR TOTHE PASSAGE, A PLURALITY OF ELONGATED MEMBERS SPACED AROUND THE PASSAGEAND PROJECTING INTO IT TRANSVERSELY TO THE DIRECTION OF AIRFLOWTTHERETHROUGH, PAIRS OF PERFORATED BAFFLES EXTENDING DOWNSTREAM OF EACHMEMBER, MEANS MOUNTING EACH PAIR OF BAFFLES ON THE CORRESPONDING MEMBERFOR RELATIVE SWINGING MOVEMENT FROM AN OPEN V POSITION, WITH THE MEMBERCONSTITUTING THE APEX OF THE V, TO A CLOSED TOGETHER POSITION, MEANS FORDISPERSING FUEL TO REACH THE V-SHAPED SPACE BETWEEN EACH PAIR OF BAFFLESWHEN OPEN FOR COMBUSTION IN THAT SPACE, AT LEAST ONE STUB DUCT EXTENDINGOUTWARDS FROM THE AXIS OF THE COMPRESSOR TO AN OUTLET CARRYING ASWIVELLING NOZZLE, AND MEANS CONNECTING SAID PASSAGE, DOWNSTREAM OF SAIDPAIRS OF BAFFLES, TO SAID STUB DUCT.
 6. A PLANT ACCORDING TO CLAIM 1 INWHICH THE ANNULAR SECTION PASSAGE IS DIVIDED INTO INNER AND OUTERANNULAR PARTS BY A PARTITION WALL EXTENDING DOWNSTREAM FROM A LEADINGEDGE SPACED FROM THE COMPRESSOR, THE OUTER PART OF THE PASSAGE BEINGCONNECTED TO SAID ONE STUB DUCT, AND THE MEMBERS CARRYING THE BAFFLESPROJECTING INTO THE OUTER PART OF THE PASSAGE ADJACENT TO THE LEADINGEDGE OF THE PARTITION WALL.